Conventional telecommunication networks typically include many calling areas to cover a particular geographic area, with communication trunks used to transfer calls between different calling areas. These communication trunks and calling areas can be operated by different companies, or exchange carriers, with some communication trunks used to interconnect different calling areas, sometimes over long distances.
Voice-over-packet technologies allow phone calls to be routed over packet networks, such as the Internet, instead of over the calling areas and trunks of conventional telecommunication networks. Wireless communication devices operating in wireless communication networks are also able to place calls using voice-over-packet technology. Calls which originate in wireless communication devices using voice-over-packet technology can be placed to other wireless communication devices, or to non-wireless telecommunication devices, such as conventional telephones communicating over the public switched telephone network (PSTN).
However, when placing voice-over-packet calls of wireless communication devices over a packet network, routing the calls can become difficult and can lead to inefficient or undesirable routing, especially when interacting with conventional circuit-switched communication trunks and calling areas. This can increase usage costs and call delays for both the users of wireless communication devices and for the operator of the wireless communication network.